Process of converting hydrocarbon oils



Feb. 16, 1937.

v A. s. PETERKIN, JR

PROCESS OF CONVERTING HYDROCARBON OILS Filed Nov. 21, 1923 I Patented Feb. 16, 1931 2,070,680

UNITED STATES PATENT OFFICE PROCESS or comm-me nrbnocannon Y oILs Albert G. Peterki'n, Jr., Bryn Mawr, Pa., assig'nor to The Atlantic Refining company, Philadelphia, Pa a corporation of Pennsylvania Application November 21. 1928, Serial No. 320,778

8 Claims. to]. 196-58) My invention relates to conversion or cracking of high boiling point hydrocarbon oils, particularly petroleum or components thereof, to produce lower boiling point oils suitable for use as of crude petroleum, residuum from a cracking operation, or heavy crude petroleum, may be economically cracked without dilution and with-' out substantial carbon deposition on the walls of the heating tubes, thereby eliminating the necesmotor fuels in internal combustion engines, with slty for cleaning and reducing replacements of 5 particular reference to the cracking of oils of the tubes. high specific gravity, more particularly residual In accordance with my invention this result is oils resulting from cracking or noncracking disattained by bringing the oil to the temperature l ions. v of incipient cracking and immediately introduc- 10 In accordance with my invention, oils of such ing it into a coking chamber, preferably not ex- 10 high boiling point, high specific gravity and obternaliy or separately heated, where the oil is jectionable solid content or other properties which maintained at elevated temperature to permit render it diillcult and relatively costly to process its cracking to form volatile products, which leave them in usual cracking systems, are converted or the chamber as vapors, and coke which is decracked with relative ease and at comparatively posited therein out of contact with externally 15 low cost to form solid coke, suitable for use as heated surfaces. fuel, lower boiling oil suitable for motor fuel or More particularly in accordance with my infor further cracking to produce motor fuel, and vention, the residual oil is brought to the temgas which may be burned or used for the producperature of incipient cracking by passage through tion of the higher alcohols and other compounds. a heating zone at such high velocity that sub 20 In cracking processes, in which the oil to be stantially no cracking occurs due to the rela-' converted into lower boiling components is passed tively short time the oil is subjected to cracking through a heated tubular passage, there is formed temperature. The .oil so heated is discharged heavy carbonaceous material which tends to adinto a coking chamber where it is maintained at e to the tube walls and form coke deposits cracking temperature, due either solely to. the 25 which impair heat transfer to the oil and may inheat absorbed while in the aforesaid heating zone duce damage to the tubes, and which must be reor to additional heat of cracked products intromoved from time to time. Such deposit of carbon duced into the coking chamber from a second occurs more readily with heavy residual oils which heating zone operated at a higher temperature.

tend form greater quantities of carbonaceous Inthe coking chamber there is eflected smoking .30

material. For this reason cracking processes are of the residual oil into coke, gas, and lower, generally practiced on distillates', as gas oil. boiling hydrocarbons, portions of which have a The heavy oils, as residues from a cracking or boiling point too high to be suitable for gasononcracking distillation, and high boiling crude line or motor fuel, and which pass as vapors oils, may be cracked by maintaining the heating from the coking chamber into suitable dephelg- 35 tubes at a relatively low cracking temperature mating equipment where they are condensed and so that mfld cracking occurs with relatively low passed to the aforesaid second heating zone concentration of heavy carbonaceous material wherein substantial cracking occurs and the and with consequent less tendency for the carhighly heated cracked products, hydrocarbons 40 bonaceous material to adhere to the tube walls. of still lower boiling point, as gasoline, thus 40 This-is an inefficient method, however, due to formed are introduced into the coking chamber.

the low yields of low boiling oils or gasoline ob- For an understanding of my invention refertained. Another mode of operation is to admix ence may be had to the accompanying. drawing withthe residual oil a diluent, as gas-oil, proillustrating diagrammatically one form 01" appa- I duced in the process and/or from an outside ratus suitable for practicing my process. a .45 source, which reducesthe concentration of heavy In the drawing, A is a furnace heated by the carbonaceous products and hence reduces carbon burner l and containing the pipe coil 2 fed by formation. The proportion of diluent required is the pump 3. B is a coking chamber, preferably however relatively too high for economical opheat insulated by covering b, into which the coil 0 eration, and may require a source of gas oil in I discharges through line I. C is a'fractionating addition to the residual oil to be cracked. 4 column into which the vapor from the coking My invention relates to improvements in chamber B is discharged through line 5. D is cracking processes whereby heavy oils, as for exa partial condenser, in communication with the ample 10 to 20' A. P..I. bottoms from distillation column C through the vapor line i, from which the line I leads to the condenser E which in turn an is connected by the line 9 to the gas separator F.

Y From the gas separator the line Ill, controlled by valve Ila, leads to suitable gas storage while the line I I controlled by valve Ila leads to liquid 5 storage.

From the bottom of the column C the line 8, in which is the pump l2, leads to the coil IS in the second furnace G or heating zone, heated by the'burner I4. The line I5, in which is the pressure reducing valve i5a, leads to and preterably extends to a point near the bottom of, the chamber B. Line l6 leads from an external supply of gas oil to the line 8.

In "the operation of the process, residual oil, for example bottoms from the noncr-acking distillation of Midcontinent crude petroleum and having a gravity of 12 in the A. P. I. scale, is fed by the pump 3 through the coil 2 wherein the oil is heated to the temperature of incipient cracking, for example 800 F., and immediately,

or before substantial cracking occurs, is discharged through the line 4 into the coking chamber B. The rate of cracking is primarily dependent upon the temperature of the oil and when the oil is at a relatively low temperature the rate of cracking is correspondingly low and therefore. little or no cracking occurs in the tubes 2. Within the chamber B is maintained a relatively low pressure, for example pounds per sq; in. gauge, and the pressure drop in the tubes 2 is preferably only suflicient to effect passage of the oil therethrough at suitably high rate. Tubes 2 are not primarily cracking tubes; they merely heat the heavy oil to the cracking temperature.

In the chamber B the oil is maintained at cracking temperature, attained in tubes 2, or supplemented by heat of or from the highly heated cracked products introduced into cham- 40 ber B through line l5 from the coil l3 in which occurs substantial cracking as hereinafter described. The maintenanc of the residual oil at the cracking temperature efiects its conversion while in the coking chamber B into lower boiling hydrocarbons, gas and solid coke. The gas andvapors of the lower boiling hydrocarbons, togetherwlth the cracked vapors introduced through the line l5, pass through line 5 into the iractionating column C where they are linel,hasaboilingrangetoohighforuse as gasoline and has in general the characteristics or gas oil. 7

The condensate irom the condenser E is passed with the uncondensed gas to the separator F from which the gas and liquid are separately withdrawn-through the lines In and II, respectively. and passed to storage or otherwise suitably disposed of or treated.

The high boiling fraction withdrawn through the line I requires further cracking to cause conversion into compounds, such as gasoline, of suitably low boiling point. Since this high boiling traction is a distillate. carbon deposition will 'lstake place much less readily cracking than would occur in the cracking of the heavy residual oil heated in the coil 2. "Therefore this oil is fed by pump I! through line.8 to the tubes I3 in which substantial cracking is eflected by bringing it to an elevated temperature, for example F., while under a high pressure, for example 850 pounds per sq. in. gauge. The length of the tubes, the pressure and the velocity are .50 adjusted or related that the. oil is maintained under cracking conditions in the, coil I3 for a sumcient period of time to permit substantial cracking with formation of appreciable quantities or practical or conunercial yields oi gasoline-like products. If desired additional quantities of charging stock suitable for high temperature cracking, as gas oil or other distillate or boiling point higher than that of gasoline,

may be fed through line It to line 8 and thence to coil l3.

The highly heated cracked products are discharged through the pressure reducing valve I541 into the low pressure coking chamber B, preterably beneath the surface'of the hot residual oil. It is not essential that the cracked products introduced at high temperature into the coking chamber pass through the residual oil; they may, for example, be introduced into the space above the liquid-oil. The introduction of this hot material from tubes l3 maintains the residual liquid oil at cracking temperature or may serve further to increase its temperature thereby causing cracking of the residual oil to occur at an increased rate. As a result the coke resulting from cracking of the heavy oil is formed in the coking chamber B, unheated except by the oils introduced into it, where it is deposited out of contact with heated surfaces.

It will thus be seen that the residual oil is cracked to form products the major portion of which are not suitable ior motor fuel but are A suitable as charging stock for a high temperature, high pressure cracking system in which relatively 'highyields of gasoline-like products are idrmed;

and the excess heat in these cracked products is utilized to maintain or increase the temperature of the hot residual liquid oil so that there are obtained additional quantities of charging stock for the more severe cracking in tubes It. The ul-' timate products from the treatment of the residual oil are coke, motor iuel and gas.

The more or less diagrammatic illustration oi. the apparatus is for purposes of description, and does not show details, such as structural modifications or features which are apparent to oneskilled in this art.

Although only one coking chamber is shown, it shall be understood that a'second chamber may be put into operation 1 8 removal of coke from the other chamber.-

It shall be understood that thesystem G, ll

generically represents any suitable method or system for cracking oil, whose reaction products may be introduced into coking chamber 13, as

herein described and preferred. or separately disposed of or further treated. My invention is therefore not limited to the particular mode described of cracking the high boiling distillate recovered from the iractionating column. For example, the cracked products from the tubes I! may be passed through intermediate apparatus for further treatment of any'kind, including cracking-before. passage to thecoking chamber B. Or the pressure reducing valve Ila. may be omitted and-the tubes It be maintained under the pressure existing in the coking chamber B,

in which may be maintained atmospheric or any suitable superatmospheric pressure.

While my inventioirhas been described by adversion to particular temperatures and pressures, it is not to be limited to these conditions which, while comprehended in my invention, are specifled merely for purpose illustration. The temperature of the heating tubes 2 should be suificient to bring the heavy oil to substantially the cracking temperature tor example, 650 to 800 F.,' while the pressure may be merely that required to force the'oil through the tubes, or a superatmospheric pressure of any suitable magnitude may be maintained in the coking chamber B. The high temperature cracking coil i3 is maintained at temperatures in excess of 800 F. and the cracking eflected in the liquid phase, un-

der high pressure, as in excess 01-100 pounds per.

square inch, or in vapor phase under lower pressure;

From the foregoing description it will be perceived that in one of its aspects my invention comprises a cracking system, including a cracking zone, such as a coking chamberB, in which occurs substantially all the cracking of the oil previously elevated to cracking temperature in a heating zone, as in heat-absorption structure 2, with production in the cracking zone of coke, lower boiling oils and gas.

In another of its aspects my invention comprises two co-operative crackingsystems, one oi them as aforesaid, and the second, operating to crack a lower boiling oil, either derived irom a separate source, an oil from the first cracking system, or the combination oi the latter with oil from a separate source, with delivery of products irom the second cracking system into the cracking zone or cokingchamber oi the first system. For brevity in the appended claims the term "residual oil refers to oil operated upon in the first cracking system and includes heavy oils of the character herein defined by that term; the term intermediate 'boiling point is employed generically to designate the oil charged into the second cracking system; and the term low boiling point is employed generically to designate oil constituting an ultimate product, such as cracked naphtha, gasoline or other oils 01' lower boiling point than that of the oll'charged into the second cracking system.

What I claim is: a

' 13A hydrocarbon oil cracking process which comprises passing the oil in 'a' restricted stream through a heating zone and heating the same.

therein to cracking temperature under suflicient pressure to maintain a substantial portion there- 'of in the liquid phase, discharging the heated oil into a separating zone and separating the same into vapors and unvaporized .01] therein, simultaneously heating'hydrocarbon yapors tovapor phase cracking temperature in a second heating oil to a vapor phase cracking operation, vaporizing and cracking the oil in the vapor phase therein, releasing the hot vapor mixture from the vapor phase cracking operation at a temperature upwards of 900 F. within a coking receptacle,

heating a heavy hydrocarbon oil to be coked to a temperature upwards of 700 F. by supplying phase cracking operation, and thereby reducing said heavy oil to coke therein.

3. In, coking heavy hydrocarbon oils, the improvem at which comprises heating the heavy oil stocib of 700 1 in a heating zone by supplying heat from an extraneous source and introducing the thus pre eated stock into a. coking receptacle, and hea g a fluid coking medium to a temperature up ards of 900 F. in a separate heating zone by s pplying heat from an extraneous source and releasing thethus heated coking medium within the coking receptacle and thereby reducing said stock to coke in the coking receptacle.

, 4. In coking heavy hydrocarbon oils. the improvement which comprises heating the heavy oil stock to be, coked to a temperature as high as 800 F. in cheating zone by supplying heat from an extraneous source and introducing the thus preheated stock into a coking receptacle, and heating a fluid coking medium to a temperature upwards of 000 F. in a separate heating zone by supplying heat from an extraneous source and to be coked to a temperature upwards the production of gasoline, the improvement which comprises heating-thetar to a temperature upwards of '7 0 F. in a heating zone by supplying heat thereto from an extraneous source and introducing the thus preheated tar into a coking receptacle, and heating a fluid coking medium to a temperature upwards of900 1". by supplying heat thereto i'rom an extraneous source in a heating zone separate from the first mentioned heating zone and releasing the thus superheated cok-' ing medium within .the coking receptacle, and thereby reducing the tar to coke in the coking receptacle.

6. The method of converting high boiling hydrocarbon oils into, lower boiling products and a coke residue which comprises, continuously 'fiowing a stream or oil consisting substantially entirely of heavy oil residues once through an elongated heated passageway while heating said stream to a cracking temperature, discharging the stream of hot products into the lower portion ,0! an enlarged chamber wherein unvaporized constituents of said stream are collected and caused to decompose to a substantially solid coke residue, simultaneously flowing a stream of oil consisting substantially entirely of distillate all stock through an independent heated passageway while heating the said stream to a temperature of at least 900 F. to eflect conversion thereof .into desired low boiling products, discharging the latter separate stream 01' highly heated cracked products into said enlarged chamber, substantial; 1y below the point oi introduction of the heavy oil residues wherein they enter into the said mass of residue below the level thereof and thus impart heat thereto to further the decomposition of said residues into coke. separately withdrawing vapors from said enlarged chamber and subjecting them to fractionation to condense as reflux condensate undesired higher boiling constituents thereof, withdrawing and condensing the fractionated vapors, and separately withdrawing reflux condensate -from said tractionating zone and passing it to said last named heated passageway as distillate charging stock therefor while in transitthrough a separate furnace to a temperature 01 at least 900 F. to eflect conversion of said condensate into lower boiling oils and introducing the heated condensate into said chamber substantially below the point or introduction oi said oil residue wherein they enter into the said mass 01' residue below the level thereof, and condensing the relatively low boilwherein they enter into the liquid retained in the coking chamberfbelow the level thereof and thus impart additional heat thereto,

ALBERT G. PETERKIN, Js.

casmmcum or connsc'rron.

5 avoiding passage-of any 01' the said residues from ing constituents of said vapors to form a light 5 said enlarged chamber to either of said'heated distillate. passageways. 8. The process of converting high boiling hy- 7. A combined cracking and coking process drocarbon oils into lower boiling ones which comfor convertinga hydrocarbon oil residue .into prises continuously passing the higher boiling coke and light distillate, which comprises heating hydrocarbon oil through a heating zone in which 10 a continuous confined stream 01 such residue in it is raised to a cracking temperature without a furnace to a cracking temperature while caustherein undergoing substantial cracking, passing ing said stream to move at a sufllcientlyrapid the oil thus heated into the lower portion of a rate to prevent substantial cracking, discharging coking zone where distillation takes place, removthe heated stream without substantial reduction ing evolved vapors irom the coking zone while 15 of pressure into the lower portion or an enlarged retaining the liquid therein, maintaining the mass chamber, removing onlyfvaporous products from in the coking. chamber to thereby convert the the chamber while retaining the liquid constitusame to a coke residue, condensing the higher ents therein and maintaining the mass in the boiling portion of the vapors removed from the chamber at acoking temperature substantially coking zone, heating the resulting condensate 20 entirely by reason'of the heated products disduring passage through a separate heating zone charged thereinto-to thereby eflect conversion to a temperature of at least 900 F. andcontinuinto a coke residue, condensing; the higher boil-- ously introducing the heated condensate into said ing portion of the vapors removed from said coking zone substantially 'below the point o in chamber, heating the resulting condensate while "troduction or the higher boiling hydrocarbon oil 25 Patent. No.; 2,070,680, February 16, 1937. l

ALBERT c .PE'rERKINf JR'.

4 It is hereby certified ithat error appears in the above numbered patent requiring correction as followsz In theheading to the drawing, 1ine3, for the filing date "Nov, 21, 1923" read Nov. 21, 1928; page 2, second column. line 6, for F .'l read 920FQ; and ,that the said Letters Patent should be read with these corrections 'therein that the same may conform to the record of the case in the Patent Office. I

Signed. and sealed this 20th day of April, A. D'. 1937;

Henry Van Arsdale Acting Commiss'ioner or Patents.

(Baal) fractionated vapors, and separately withdrawing reflux condensate -from said tractionating zone and passing it to said last named heated passageway as distillate charging stock therefor while in transitthrough a separate furnace to a temperature 01 at least 900 F. to eflect conversion of said condensate into lower boiling oils and introducing the heated condensate into said chamber substantially below the point or introduction oi said oil residue wherein they enter into the said mass 01' residue below the level thereof, and condensing the relatively low boilwherein they enter into the liquid retained in the coking chamberfbelow the level thereof and thus impart additional heat thereto,

ALBERT G. PETERKIN, Js.

casmmcum or connsc'rron.

5 avoiding passage-of any 01' the said residues from ing constituents of said vapors to form a light 5 said enlarged chamber to either of said'heated distillate. passageways. 8. The process of converting high boiling hy- 7. A combined cracking and coking process drocarbon oils into lower boiling ones which comfor convertinga hydrocarbon oil residue .into prises continuously passing the higher boiling coke and light distillate, which comprises heating hydrocarbon oil through a heating zone in which 10 a continuous confined stream 01 such residue in it is raised to a cracking temperature without a furnace to a cracking temperature while caustherein undergoing substantial cracking, passing ing said stream to move at a sufllcientlyrapid the oil thus heated into the lower portion of a rate to prevent substantial cracking, discharging coking zone where distillation takes place, removthe heated stream without substantial reduction ing evolved vapors irom the coking zone while 15 of pressure into the lower portion or an enlarged retaining the liquid therein, maintaining the mass chamber, removing onlyfvaporous products from in the coking. chamber to thereby convert the the chamber while retaining the liquid constitusame to a coke residue, condensing the higher ents therein and maintaining the mass in the boiling portion of the vapors removed from the chamber at acoking temperature substantially coking zone, heating the resulting condensate 20 entirely by reason'of the heated products disduring e through a separate heating zone charged thereinto-to thereby eflect conversion to a temperature of at least 900 F. andcontinuinto a coke residue, condensing; the higher boil-- ously introducing the heated condensate into said ing portion of the vapors removed from said coking zone substantially 'below the point o in chamber, heating the resulting condensate while "troduction or the higher boiling hydrocarbon oil 25 Patent. No.; 2,070,680, February 16, 1937. l

ALBERT c .PE'rERKINf JR'.

4 It is hereby certified ithat error appears in the above numbered patent requiring correction as followsz In theheading to the drawing, 1ine3, for the filing date "Nov, 21, 1923" read Nov. 21, 1928; page 2, second column. line 6, for F .'l read 920FQ; and ,that the said Letters Patent should be read with these corrections 'therein that the same may conform to the record of the case in the Patent Office. I

Signed. and sealed this 20th day of April, A. D'. 1937;

Henry Van Arsdale Acting Commiss'ioner or Patents.

(Baal) 

